In recent years, as a technique of producing display devices which display images and the like, generally used is a roll-to-roll method which produces a display device in a continuous manner by transporting a substrate in a form of film which is guided by a roller in a cylindrical shape. Development of process of deposition etc. or development of materials for the substrate, as well as development of hardware for manufacturing devices is proceeding simultaneously. Particularly, for the material for the substrate, assays of using thinner substrates from a viewpoint of weight saving, and development of materials which are resistant to broad range of processing temperature are proceeding. Lately, thin film glass (glass film) excellent in gas barrier property or in translucency which is capable of being processed in a high temperature compared to a resin, and at the same time, capable of being bent as a resin film, is being developed, and thus, realization of devices with properties and characteristics which has not been available in conventional techniques are expected.
Examples for use of the roll-to-roll method includes the sputtering device disclosed in patent document 1 (see FIG. 1). This sputtering device comprises a delivering/winding chamber and a deposition roller (coating drum). In this device, a film is rolled out from a film roll in the delivering/winding chamber, and then transported with being wound on the deposition roller. The film is subjected to a sputtering deposition, and then wound up to the roll in the delivering/winding chamber again. Around the deposition roller, plural numbers of coating chambers are provided, each chamber having a sputter source disposed thereto. A film of plural layers can be formed by running the film one cycle. Each of the chambers comprises a vacuum evacuation pump. Partition walls are each provided between coating chambers, and between each of the coating chambers and the delivering/winding chamber. These partition walls are disposed in front of the deposition roller adjacently. By being adjacent to the deposition roller (with about some mm of space), these partition walls allow each coating chamber to maintain its independence of the atmosphere from each other, and to form a film different from that formed by the adjacent chamber. For a long time, resin films having a low thermal resistance have generally been objects subjected to the continuous processing of such a roll-to-roll method. In order to protect the resin films from damage by heat, deposition rollers have been cooled in many of such cases.
However, in recent years, it is being requested to perform the operation with a raised temperature of the deposition roller, in order to obtain a good film quality. In particular, with the development of resin films with higher thermal resistance such as polyimide, or thin glass of 100 μm or less capable of being subjected to a roll-to-roll processing, it is sometimes requested that the deposition roller is resistant to high temperature, for example, of up to 300° C., in order to make the best use of these thermal resistance. In a film deposition on a metal foil, even higher temperature is sometimes required. Meanwhile, there has also been a request to cool the deposition roller down to a temperature of below 0, in order to execute the treatment on an ordinary resin film at a high speed. As thus explained, there has been an increased demand for the deposition roller to be operated in broad range of temperature.
Generally, in a deposition roller, a temperature control is conducted for the substrate to have a temperature necessary for a process of deposition treatment. This temperature control is conducted by uniformly raising and lowering the temperature of outer cylindrical surface of a roll in a cylindrical shape in which accuracy in the outer diameter or cylindricity is secured by machine processing. In such conventional deposition roller, when the temperature-control region for raising temperature and lowering temperature is broadened, the following problems of 1 to 3 arise.
1) Due to a thermal expansion, change in outer diameter of cylindrical surface of the deposition roller occurs on some mm scale. That will result in a deviation in running speed or running distance of the film which is controlled by rotation of the deposition roller.
2) The deposition roller loses the accuracy in cylindricity, resulting in problems in quality of transportation such as meandering of the film.
3) In a device such as the sputtering device of the patent document 1, which comprises plural partition walls and small spaces between these partition walls and the deposition roller, the spaces between the deposition roller and each partition wall will be changed by being influenced by the change of outer diameter of the deposition roller. As a result, the properties of partition walls vary. In the worst case, the deposition roller and a partition wall contact with each other.